Walrus ethology. II. Herd structure and activity budgets of summering males

1976 ◽  
Vol 54 (5) ◽  
pp. 704-715 ◽  
Author(s):  
Edward H. Miller
Keyword(s):  
Shallow Water ◽  
Breeding Season ◽  
Social Activity ◽  
Agonistic Interactions ◽  
Body Contact ◽  
Odobenus Rosmarus ◽  
Herd Structure ◽  
Heat Conservation ◽  
Extensive Body ◽  
Structure And Activity

Male walruses, Odobenus rosmarus (L.), summering (outside the breeding season) at an Alaskan hauling ground, use all available kinds of beach habitat: cobble and boulder beaches, rock benches, and large boulders. Formation and dissolution of large herds on land can occur rapidly. Walruses are very gregarious and positively thigmotactic. In cool weather about 98% of walruses on land lie in passive body contact with other walruses. Dominant walruses (large, with long unbroken tusks) are most successful in entering herds on land, and in keeping positions in them. This results in overrepresentation of subordinates in the periphery of herds. Agonistic interactions occupy 5–10% of the time of walruses in large herds on land, and cause local disturbances that lead to agonistic involvement of up to 20 animals. Fewer kinds of social activity occur on land than in water. On land and in shallow water, small walruses are generally more active than large ones. Extensive body contact while they are hauled out is chiefly an adaptation for heat conservation and may also facilitate molting. The extreme gregariousness of walruses may have evolved because individuals joining large herds have a greater probability of achieving extensive body contact than have those joining small herds.

Observations on social behaviour of Atlantic walruses (Odobenus rosmarus (L.)) during terrestrial haul-out

1980 ◽  
Vol 58 (3) ◽  
pp. 461-463 ◽  
Author(s):  
R. E. Salter
Keyword(s):  
Social Interactions ◽  
Social Behaviour ◽  
East Coast ◽  
Adult Males ◽  
Agonistic Interactions ◽  
Age Composition ◽  
Body Contact ◽  
Adult Females ◽  
Odobenus Rosmarus

Social interactions in walrus herds of mixed sex and age composition were recorded at a haul-out site on the east coast of Bathurst Island, N.W.T., during July–August 1977. Most walruses maintained body contact with at least one other walrus while hauled out on land; herds were usually circular in shape. Adult males, adult females, and immatures all displaced other walruses, and thus entered herds, by jabbing with the tusks. Dominance during agonistic interactions was related to relative tusk length and sex and age of interactants. Behaviour of walruses on land suggested an energetic advantage in mutual body contact, which would be maximized by occupation of interior positions within herds.

Buoyancy in the LumpsuckerCyclopterus Lumpus

1986 ◽  
Vol 66 (1) ◽  
pp. 159-174 ◽  
Author(s):  
John Davenport ◽  
Elin Kjørsvik
Keyword(s):  
Shallow Water ◽  
Breeding Season ◽  
Deep Water ◽  
Adult Life ◽  
Male Parent ◽  
Demersal Eggs ◽  
Cyclopterus Lumpus ◽  
Mode Of Life ◽  
Rocky Bottoms

The lumpsucker or lumpfish,Cyclopterus lumpusL. (Cyclopteridae, Scorpaeniformes), is a cottoid teleost, and, like other fish in its family, exhibits many characteristics of a coastal, bottom-dwelling fish. It is globiform, has no swimbladder, possesses a large abdominal sucker (formed from the pelvic fins), and lays demersal eggs which are brooded by the male parent for many weeks (Fulton, 1907; Cox & Anderson, 1922; Yesipov, 1937; Zhitenev, 1970; Mochek, 1973). The species spends the breeding season in shallow water, where both sexes may be seen attached to the rocks by their suckers. Early researchers (Couch, 1863; Day, 1880–4; Smitt, 1892) believed that the adults retreated to rocky bottoms in deep water after breeding. However, later workers (Cox & Anderson, 1922; Saemundsson, 1926, 1949; Andriyashev, 1954; Bagge, 1964; Blacker, 1983; Daborn & Gregory, 1983) have demonstrated that the lumpsucker spends much of its larval and adult life living epipelagically and in mid water in coastal and oceanic areas upon macrozooplankton (e.g. ctenophores, mysids). The term ‘semi-pelagic’ seems the most appropriate label for its mode of life.

Pre-slaughter social activity of young bulls relating to the occurrence of dark-cutting beef

1988 ◽  
Vol 46 (2) ◽  
pp. 153-161 ◽  
Author(s):  
C. Franc ◽  
L. Bartoš ◽  
Z. Hanyš ◽  
Z. Tomeš
Keyword(s):  
Social Interactions ◽  
Social Activity ◽  
Water Holding Capacity ◽  
The Other ◽  
Longissimus Dorsi ◽  
Agonistic Interactions ◽  
Ph Values ◽  
Muscle Ph ◽  
Light Reflectance ◽  
Water Holding

AbstractTwenty bulls of three different breeds were tethered individually from 5 months until slaughter at 21 months. On the day of slaughter, the bulls were divided into groups of five animals, transported and then released in a pen. The first bull of the group was slaughtered 60 or 110 min after regrouping. Subsequent bulls were slaughtered individually at 50-min intervals. Social interactions among the bulls were recorded. Muscle pH, light reflectance values and water-holding capacity were measured in samples of m. longissimus dorsi. These characteristics showed correlations with the amount of non-agonistic social activity in which a bull had been involved before slaughter. The characteristics were also correlated with the number of agonistic interactions. Whether a bull was behaving as a dominant or a submissive animal did not influence the incidence of dark-cutting meat as judged by pH values. On the other hand, light reflectance values and water-holding capacity were correlated with the number of passive agonistic interactions (i.e. how many times a bull was attacked) and considerably less with the number of active interactions (number of attacks by the bull). The incidence of butting was not significantly related to muscle characteristics but mounting was significantly correlated with them.The study indicates that dark-cutting beef is primarily caused by physically exhausting activities such as mounting, and further modified by stress-inducing social interactions.

Evidence of stereotyped underwater vocalizations of male Atlantic walruses (Odobenus rosmarus rosmarus)

1987 ◽  
Vol 65 (9) ◽  
pp. 2311-2321 ◽  
Author(s):  
Ian Stirling ◽  
Wendy Calvert ◽  
Cheryl Spencer
Keyword(s):  
Breeding Season ◽  
Adult Male ◽  
Whole Body ◽  
Individual Male ◽  
Odobenus Rosmarus ◽  
Number Pattern ◽  
The Individual ◽  
Odobenus Rosmarus Rosmarus

Adult male Atlantic walruses (Odobenus rosmarus rosmarus) vocalize extensively underwater during the breeding season. The individual calls are composed of one or more short repetitious pulses which may vary individually in the number, pattern, and rate at which they are given. Individual male walruses give repeated stereotyped vocalization cycles totalling several hundred pulses each for up to several hours at a time, both while the whole body is submerged and between breaths with the head submerged while at the surface. We analyzed the vocalization cycles of a sample of different walruses, and sound spectrograms of particular calls from within those cycles, to test the hypothesis that the stereotyped vocalizations of individuals are unique and recognizable. In our sample, the pulse patterns of particular calls given by individual walruses in a series of vocalization cycles were nearly identical but were consistently different from the same call given by other animals. One call, the diving vocalization of a recognizable male, was identical in two different years.

Étude du marquage olfactif chez la marmotte commune (Marmota monax) en captivité

1983 ◽  
Vol 61 (8) ◽  
pp. 1720-1725 ◽  
Author(s):  
Paule Hébert ◽  
Jacques Prescott
Keyword(s):  
Breeding Season ◽  
Scent Marking ◽  
Direct Relation ◽  
Agonistic Interactions ◽  
Positive Correlation ◽  
Marmota Monax ◽  
Captive Group ◽  
The Individual ◽  
Similar Decrease ◽  
Breeding Status

The study of a captive group of woodchucks (Marmota monax) has confirmed the occurrence in this species of a cheek- and chin-rubbing behaviour associated with scent marking. The frequency of this behaviour is high in the spring breeding season and decreases markedly during summer, following a similar decrease in breeding activities. We found no direct relation between hierarchical status and scent-marking rates of individual woodchucks whereas a positive correlation was found between monthly rates of scent marking and agonistic interactions. Dominant individuals sometimes scent marked after agonistic encounters. Scent marking occurred most often during exploration and all individuals used the same marking sites: along paths between burrows and at burrow entrances. Despite the limitations imposed by our captivity conditions, our results seem to agree with the following hypotheses: (i) scent marking could contribute to inform conspecifics about the breeding status of each individual; (ii) in certain circumstances, it may constitute an agonistic signal and enhance the expression of dominance; (iii) it could contribute to the familiarization of the individual with its own environment.

Behaviour of the Koala, Phascolarctos cinereus (Goldfuss), in CAptivity V*. Sexual Behaviour

1980 ◽  
Vol 7 (1) ◽  
pp. 41 ◽  
Author(s):  
M Smith
Keyword(s):  
Breeding Season ◽  
Sexual Behaviour ◽  
Courtship Behaviour ◽  
Vertical Position ◽  
Agonistic Interactions ◽  
Phascolarctos Cinereus ◽  
Penile Erections ◽  
In Captivity

At the height of the breeding season male koalas frequently attempted copulation. These attempts were often apparently spontaneous, but many followed bellowing or agonistic interactions. Sexual behaviour began at 3 y old in males, except for penile erections, which sometimes occurred in younger males. Males performed no courtship behaviour. Behavioural oestrus was brief, and consisted of four distinct types of activity: jerking, bellowing, mild aggression towards the male, and pseudomale behaviour. Oestrous females could become very excited by the presence of a male, and the four activities were very flexible in their expression. Copulation itself was quite brief and consisted of mounting, thrusting, convulsions, and disengagement. The pair were always in a vertical position in a tree, the male grasping the female's neck in his jaws.

Underwater vocalizations of ice breeding grey seals

1993 ◽  
Vol 71 (11) ◽  
pp. 2211-2219 ◽  
Author(s):  
Sylvie Asselin ◽  
Mike O. Hammill ◽  
Cyrille Barrette
Keyword(s):  
Breeding Season ◽  
Seasonal Variations ◽  
Temporal Structure ◽  
Social Activity ◽  
Low Frequency ◽  
Ice Cover ◽  
Halichoerus Grypus ◽  
Vocal Repertoire ◽  
Night And Day

Grey seals (Halichoerus grypus) breed both on land and on the ice. In January 1991, 36 h of underwater recordings were made from Amet Island, located in ice-covered waters in the southern Gulf of St. Lawrence. All vocalizations were examined for spectral and temporal structure and then classified into 1 of 7 call types. The majority of calls consisted of guttural "rups" and "rupes" (frequency = 100–3000 Hz), and low-frequency growls (100–500 Hz). Other less common vocalizations were low-frequency clicks (3000 Hz), as well as loud knocks, similar to knocking vocalizations recorded in walrus, and which had not been described previously for grey seals. The total number of vocalizations and the number of specific call types showed seasonal variations. The rate of vocalizations increased with the intensity of social activity and with the number of agonistic behaviors during the progression of the breeding season. Comparisons between night and day showed some changes in the vocal repertoire. Low-frequency clicks were recorded more often during darkness (17.1% of calls) than in daylight (1.9%), and when ice cover was more extensive.

Correlative transmission and high-resolution scanning electron microscopic studies on pituitary cells

1990 ◽  
Vol 48 (3) ◽  
pp. 20-21
Author(s):  
S. Tai
Keyword(s):  
Cell Types ◽  
Depth Of Field ◽  
Secretory Cells ◽  
Specific Cell ◽  
Pituitary Cells ◽  
Electron Microscopic ◽  
3 Dimensional ◽  
Microscopic Studies ◽  
Structure And Activity ◽  
Intracellular Structure

Extensive cytological and histological research, correlated with physiological experimental analysis, have been done on the anterior pituitaries of many different vertebrates which have provided the knowledge to create the concept that specific cell types synthesize, store and release their specific hormones. These hormones are stored in or associated with granules. Nevertheless, there are still many doubts - that need further studies, specially on the ultrastructure and physiology of these endocrine cells during the process of synthesis, transport and secretion, whereas some new methods may provide the information about the intracellular structure and activity in detail.In the present work, ultrastructural study of the hormone-secretory cells of chicken pituitaries have been done by using TEM as well as HR-SEM, to correlate the informations obtained from 2-dimensional TEM micrography with the 3-dimensional SEM topographic images, which have a continous surface with larger depth of field that - offers the adventage to interpretate some intracellular structures which were not possible to see using TEM.

Activity Engagement in Cognitive Aging: A Review of the Evidence

2013 ◽  
Vol 23 (1) ◽  
pp. 1-12 ◽  
Author(s):  
Yvonne Rogalski ◽  
Muriel Quintana
Keyword(s):  
Older Adults ◽  
Cognitive Decline ◽  
Cognitive Aging ◽  
Social Activity ◽  
Current Evidence ◽  
Omega 3 ◽  
Neuroprotective Effects ◽  
Activity Engagement ◽  
Age Related ◽  
Age Related Cognitive Decline

The population of older adults is rapidly increasing, as is the number and type of products and interventions proposed to prevent or reduce the risk of age-related cognitive decline. Advocacy and prevention are part of the American Speech-Language-Hearing Association’s (ASHA’s) scope of practice documents, and speech-language pathologists must have basic awareness of the evidence contributing to healthy cognitive aging. In this article, we provide a brief overview outlining the evidence on activity engagement and its effects on cognition in older adults. We explore the current evidence around the activities of eating and drinking with a discussion on the potential benefits of omega-3 fatty acids, polyphenols, alcohol, and coffee. We investigate the evidence on the hypothesized neuroprotective effects of social activity, the evidence on computerized cognitive training, and the emerging behavioral and neuroimaging evidence on physical activity. We conclude that actively aging using a combination of several strategies may be our best line of defense against cognitive decline.

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